MessageSeal

MessageSeal helps you protect text before sharing it through the apps you already use. Encrypt a message for selected recipients, or sign readable text so others can check its signature.

PROTECT AND SHARE
Write your message in Compose, choose Encrypt or Sign, and share the result through Messages, Mail, or another app. Use Open to decrypt encrypted messages or verify signed text. The included Messages extension lets you encrypt, sign, share public identities, and open compatible protected text inside Messages.

YOUR KEYS, YOUR DEVICE
Create your own identities in Keys and save other people's public identities in People. Private keys are stored in the device Keychain. Manage multiple identities, create password-protected encrypted backups, and use dedicated temporary identities for one-off exchanges.

EXCHANGE PUBLIC IDENTITIES NEARBY
When two devices are together, use Nearby Exchange to exchange public identities and compare a matching safety code before saving. Nearby Exchange runs in the main app while its screen is open.

LOCAL BY DESIGN
Encryption, signing, decryption, and verification happen on your device. No account, advertising, analytics, or cloud sync. Optional device authentication helps protect access to your keys and opened messages. A guided tour and Help & Security guide explain each step.

The current crypto profile uses Apple's XWing HPKE to wrap message keys, AES-256-GCM to protect message text, and hybrid ML-DSA87 + P521 signatures.

MessageSeal protects text contents. The app you use to transport a message may still retain copies and transport metadata. Signed text remains readable. A valid signature or matching safety code does not establish a person's name by itself; confirm public identities through a trusted channel before relying on them.

Requires iOS or iPadOS 26.0 or later.